Trisazo dye.



UNITED STATES Patented December 29, 1903.

PATENT OFFICE.

ADOLF ISRAEL AND RICHARD KOTHE, OF ELBERFELD, GERMANY, ASSIGNORS TO FARBENFABRIKEN OF ELBERFELD (30., OF NEW YORK, N. Y., GOR- PORATION NEW YORK.

TRISAZO DYE.

SPECIFICATION forming part of Letters Patent No. 748,076, dated December 29, 1903- Application filed April 2, 1903. Serial No. 150,754. (Specimens) 7 To all whom it may concern.-

Be it known that we, ADOLF ISRAEL and RICHARD KOTHE, (assignors to the FARBEN- FABRIKEN OF ELBERFELD COMPANY, of New 5 York,) residing at Elberfeld, Germany, have invented a new and useful Improvement in Trisazo Dyes; and we hereby declare the following to be a clear and exact description of our invention.

1 Our invention relates to the production of new and valuable trisazo dyestuffs derived from 1 acetylamido 2 4 diamidobenzene, which body is described in application for Letters Patent, Serial No. 150,7 63, filed April I5 2, 1903. These new trisazo dyestuffs have the following general formula:

P meaning the radical of a paradiamin-such as of para-phenylenediamin, para-diamidodiphenylamin, benzidin, tolidin, dianisidin, or the like-X meaning the radical of l-acetylamido-2-4- diamidobenzene, which can be once replaced by a base capable of combin- 0 ing with diazo compounds. Of these bases we cite the following as typical: meta-phenylenediamin, chloro meta phenylenediamin, meta-toluylenediamin, 2 4 diamidoanisol, alpha-naphthylamin, or the like.

The new process for preparing these dyestufls consists in combining the tetrazolized azo dyestufis derived from a para-diarnin and one molecule of gamma-amidonaphthol sul- V fonic acid either with two molecules of 1- 4o acetylamido2-4-diamidobenzene, or at first with one molecule of this body and then with one molecule of one of the above-cited bases, or at first with one molecule of one of these bases and then with one molecule of l-acetylamido-2-4-diamidobenzene.

The dyestuifs produced in the above-defined manner are dark powders,which dissolve From the resulting azo dyestuff the acetyl group is split off in the usual way by boiling it with caustic-soda lye. The monoazo dyestuff thus produced having the formula is then tetrazotized by means of fourteen parts of sodium nitrite and sixty parts of hydrochloric acid, (twenty per cent.) The tetrazo compound thus prepared is then mixed with an aqueous solution of fifty parts of crystallized sodium acetate and an aqueous solution of 16.5 parts of l-acetylamido-2z4- diamidobenzene. When the formation of the intermediate compound is completed, a solution of 12.2 parts of meta-toluylenediamin containing an excess of sodium carbonate is added. After being stirred for a short time the new dyestuff is precipitated by the addition of common salt, filtered off, and dried.

The new trisazo coloring-matter has in a free state the following formula:

ns-coon, 1

which, in the shape of the sodium salt, is a dark powder, soluble in water with a bluishblack color, assuming a greener tint by the addition of ammonia. It is soluble in concentrated sulfuric acid of 66 Baum witha blue color, a reddish-black precipitate being obtained by the addition of ice. It dyes unmordanted cotton deep-black shades.

Having now described our invention and in what manner the same is to be performed, what we claim as new, and desire to secure by Letters Patent, is-

l. The herein-described new trisazo dyestuffs which are alkaline salts of acids having the above-defined general formula, and which are dark powders, soluble in water with a bluish-black color; dyeing unmordanted cotton from brownish-black to bluishblack to black shades, substantially as described.

2. The herein-described new trisazo dyestufi, being an alkaline salt of an acid having the above-defined formula which, in the shape of the sodium salt, is a dark powder, soluble in water with a bluish-black color assuming a greener tint by the addition of ammonia; being soluble in concentrated sulfuric acid of 66 Baum with a blue color, a reddish-black precipitate being obtained therefrom by the addition of ice dyeing unmordanted cotton deep-black shades, substantially as hereinbefore described.

In testimony whereof we have signed our names in the presence of two subscribing witnesses.

ADOLF ISRAEL. RICHARD KOTHE.

Witnesses:

OTTO KONIG, ALBERT HEMSING. 

